Super soldiers

Super soldiers

Scientists have found the part of the brain that controls “effortful” behavior and have learned to stimulate it. The result is, in tests on mice, scientists have been able to turn shy, passive beta mice into bold and aggressive alpha mice that almost always win in contests of competitive dominance and effort.

In an article published in the journal Science, researchers describe how they found that mice that won a dominance competition in a “tube test” showed activity in the portion of the brain called the dorsomedial prefrontal cortex (dmPFC), which is associated with “effortful behavior” and “social dominance.” In a tube test, two mice are placed in both ends of a tube that is sized so as to not allow them to pass each other. The mice push on one another until one or the other reaches the end of the tube and exits. The mouse that pushes the most mice aside will win the dominance game. Mice whose dmPFC was quiet during the tube test always lost the tube test.

Neuroscientist Zhou Tingting of the Chinese Academy of Sciences, Shanghai, and his colleagues learned that they could take “loser” mice and use a brain stimulation technique that triggers neural activity in the dmPFC and those mice would then win the tube test almost every time, even against the most dominate mouse.

The researchers determined that much more than physical strength was at play in determining the winners and losers. Once they became winners, some mice continued to win even after the brain stimulations stopped.